RLC bridge

I know a brand new Lecroy (IIRC 9000 series) sitting on a shelf in a storage room because it has no peak detect. Using a fixed sample rate would require an insane amount of memory and very slow update times. Peak-detect / envelope (which is sometimes not the same!) is the only way to go.

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
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That's because they are very good, much less noise than any of the Tek scopes I have seen.

For low-frequency work you can get even less noise by turning on the

20MHz bandwidth filter and/or high resolution mode. And then there is a stange effect. It's hard to see the trace updating, because there is no per-sweep change to the trace. The noise is too low!

--

John Devereux

On a sunny day (Fri, 23 Mar 2012 15:21:37 -0700) it happened Joerg wrote in :

days.

waveform.

record it on tape too.

phenomenal

Wrong, I had a video recorder at home, Philips's first: LDL1000

1/2 inch tape, I think it was 1500 guilders at that time. The Sony Umatic just appeared right then, quickly followed by the Philips cassete player, VHS and Betamax. ldl-1000 totaal01.html 1969:

I had one and modified it for color. There also was the Akai that recorded video on normal audio tape IIRC. An other helical scan. Scroll down, 1969:

There were a lot, and many people had one.

They do speak Dutch, but the Dutch do not normally speak Fries.

days.

displays

waveform.

kHz

record it on tape too.

phenomenal

Neat! I never knew these existed.

The Dutch generally have trouble speaking Dutch. There are so many dialects. They can even have their own language in a small town!

--
Failure does not prove something is impossible, failure simply
indicates you are not using the right tools...
nico@nctdevpuntnl (punt=.)
--------------------------------------------------------------

On a sunny day (Sat, 24 Mar 2012 15:16:55 GMT) it happened snipped-for-privacy@puntnl.niks (Nico Coesel) wrote in :

It was a very neat machine, Philips excelled itself on it. I measured the bandwidth once, and it was more than 2 MHz, and did not have any of the horrible artifacts that modern mpeg or H264 has,

2MHz would give a very nice noise free BW picture. Mostly discrete components, no capstan servo, just a head servo, FM video recording, and surprise, to control the rotating head speed an aluminum disk with an electro magnet as electromagnetic break system. They did the same for the reels, rotating permanent magnet and the reels had alu disks, the drive motor was moved left and right on rails so it would cover more of the alu disk of the take up - or supply reel, and that is how the tape tension was maintained, and fast forward and reverse, just move the motor. No belts anywhere, could have lasted forever, sold it.

supply reel take up reel ============ ============= | | | ===== | --------- | ----------- alu disks ===== | 2 rotating sets of permanent magnets ------- | | 50 Hz motor on rails | | ------- ================= rails

Amazing, never seen that anywhere since then. Philips could make really incredible stuff if they wanted to.

The descriptions at the prototype parts distributors aren't all that accurate anymore these days.

Analog scopes can be the only suitable tool in some situations. But if you rarely do RF stuff it's understandable to not see much use in them. I believe most of your work is pulsed signals, that's where samplers and DSOs are the tools du jour. For noise debug they aren't all that useful.

--
Regards, Joerg

http://www.analogconsultants.com/

The alternatives are Tek 2465 scopes. That supply is obviously limited, and dwindling. There comes a point where you have to buy a new analog scope. For university labs that point has arrived more than a decade ago because many of those are not allowed to buy at auction, their central procurement office demands written offers which EBay sellers typically won't (or can't) do.

[...]

--
Regards, Joerg

http://www.analogconsultants.com/

window

days.

displays

waveform.

kHz

record it on tape too.

phenomenal

We had something similar (but American, AFAIR) at school and it cost a lot more. Even 1500 guilders was a ton of dough back then, like three months worth of rent. Most families could not afford something like that.

When I worked in Hengelo and talked with one of the other Zuid Limburgers a bit too fast none of our co-workers could follow the conversation. What really stunned me: One day two of us were listening to an Urbanus tape, laughing and almost rolling on the floor. The others sat there stoned-faced, couldn't understand a thing.

--
Regards, Joerg

http://www.analogconsultants.com/

On a sunny day (Sat, 24 Mar 2012 11:19:30 -0700) it happened Joerg wrote in :

A color set around 1967, when color started in the Netherlands and Germany, did cost about 3000 guilders IIRC. Do you know how many were sold? You must have been from a very poor background.

I already build one from parts in 1969, with a reject CRT from the studio, was reject for studio work, but very good for home :-) The parts was Philips parts from a well known Amsterdam dump shop. Very very good stuff. All tubes of course.

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Why not? A digital scope will show you almost anything that an analog scope will, plus it will do signal averaging, RMS measurement, and save pictures! An untriggered sampling scope measures RMS noise nicely.

The real noise tool is a spectrum analyzer, which is usually digital nowadays, too.

--

John Larkin, President       Highland Technology Inc
www.highlandtechnology.com   jlarkin at highlandtechnology dot com   

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME  analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

^^^^^^^^

That's the key word.

It is next to impossible to see occasional and erratically pulsating fuzz on a sliver of an ultrasound pulse train with a DSO. Such stuff can have energies 80dB or more under the transmit energy yet it'll show up in the Doppler spectrum and then customers would bitch about that.

It usually isn't. The whole front-end is analog until stuff has been mixed down to where 24-bit converters are affordable. On my new one that is 250kHz but the whole analyzer goes to over 4GHz.

Also, just about the only analyzer that can truly see "fuzz" on pulse trains is the HP-3585. And only if the thing is screeming in pain because of input overload. Sometimes I tell engineers "Now you might want to look to the side when I do this". I also make sure that the client understands that we are hardcore redlining it and might blow the input. And still, there is residual stuff it won't see and only a Tek

2465 or a similar scope will see.

--
Regards, Joerg

http://www.analogconsultants.com/

Which costs around $1500 AFAIK. I was never all that enthused with SRS gear. My old HP4191 goes to a GHz and on the used equipment market they aren't too much more expensive.

--
Regards, Joerg

http://www.analogconsultants.com/

just

almost every day,

If it is just a 200 MHz DSO that is a very nice price. If it were a decent 200 MHz analog scope that price would be impressive to say the least. Do both at that price? That strains believability. 'bout 1600 GBP.

?-)

Or, for as seldom it'll get used, eBay.

That's a good thing, too. Keeps prices low.

IME, engineers tend not to take cal certs on trust, and check things out for themselves before relying on readings.

I've seen some real horrors hiding behind cal seals.

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

Wasn't it Philips that invented the rotating transformer for video head drum signals, that everybody finished up using?

--
"For a successful technology, reality must take precedence 
over public relations, for nature cannot be fooled."
                                       (Richard Feynman)

On a sunny day (Sat, 24 Mar 2012 13:34:22 -0700) it happened Fred Abse wrote in :

The LDL1000 had the rotating transformer (2 potcore halves basically), but I do not know if Philips invented it.

It isn't that seldom. The 2465 scopes from auctions are often rather tired ones. Like a good car but with half a million miles on it. Sometimes what we got needed a complete knew set of knobs, once the delayed trigger clutch broke, stuff ike that. Shipping alone decimates the available supply, I've seen cases where CRTs were literally crushed and chassis bent.

I've had cases where engineers wouldn't let go of it once they got their hands on a 2465 and I had shown them the ropes. DSOs are like DTV, you either get a good picture, a blocky one with botched content, or a blue screen. Analog shows you the stuff in between.

Yeah, but a lot of times we the taxpayers end up paying for that.

--
Regards, Joerg

http://www.analogconsultants.com/

every day,

This is it's little 100MHz brother:

The 2008 was somewhere between $3k and $4k I think and I believe was replaced by a newer model. What the future of this series is with the new owner of the company I don't know.

--
Regards, Joerg

http://www.analogconsultants.com/